Compositions for protecting plants against disease

Abstract

Novel benzo-1,2,3-thiadiazole-7-carboxylic acid esters of formula ##STR1## in which Y is oxygen or sulfur; Q 1 and Q 2 independently of one another are each hydrogen or halogen; R 1 and R 2 independently of one another are each hydrogen or C 1 -C 4 alkyl; X 1 is hydrogen, halogen, C 1 -C 4 alkyl, trifluoromethyl, C 1 -C 3 alkyl, C 1 -C 2 alkoxy halo-substituted in the alkyl moiety, nitro, cyano, dimethylamino, phenyl, phenoxy, or phenyl or phenoxy each substituted by halogen and/or by C 1 -C 2 alkyl and/or by C 1 -C 2 alkoxy; X 2 is hydrogen, halogen or methyl; X 3 is hydrogen or halogen; and A comprises the bridge member ##STR2## R 5 is C 1 -C 6 alkyl, C 3 -C 6 cycloalkyl, C 1 -C 6 alkoxy, phenyl, or phenyl substituted by halogen or methoxy; R 6 is C 1 -C 6 alkyl or C 1 -C 6 alkoxy; ##STR3## that together represents a saturated or unsaturated 3- to 7-membered heterocycle W 3 having a maximum of 2 oxygen or sulfur atoms as additional hetero atoms. The novel active ingredients have plant-protecting properties and are suitable especially for the preventive protection of plants against attack by phytopathogenic microorganisms such as fungi, bacteria and viruses.

What is claimed is: 
     
       1. A compound of formula I ##STR92## in which Y is oxygen or sulfur; Q 1  and Q 2  independently of one another are each hydrogen or halogen;   R 1  and R 2  independently of one another are each hydrogen or C 1  -C 4  alkyl;   X 1  is hydrogen, halogen, C 1  -C 4  alkyl, trifluoromethyl, C 1  -C 3  alkoxy, C 1  -C 2  alkoxy halo-substituted in the alkyl moiety, nitro, cyano, dimethylamino, phenyl, phenoxy, or phenyl or phenoxy each substituted by halogen and/or by C 1  -C 2  alkyl and/or by C 1  -C 2  alkoxy;   X 2  is hydrogen, halogen or methyl;   X 3  is hydrogen or halogen; and   A is --Si(R 5 )(R 6 ), wherein   R 5  is C 1  -C 6  alkyl, C 3  -C 6  cycloalkyl, C 1  -C 6  alkoxy, phenyl, or phenyl substituted by halogen or methoxy;   R 6  is C 1  -C 6  alkyl or C 1  -C 6  alkoxy; or alternatively R 5  and R 6  together represent a saturated 5- to 7-membered heterocycle having a maximum of 2 oxygen or sulfur atoms as additional hetero atoms.     
     
     
       2. A compound according to claim 1, wherein R 5  is C 1  -C 3  alkyl, C 1  -C 4  alkoxy, phenyl or fluorophenyl; and R 6  is C 1  -C 3  alkyl or C 1  -C 4  alkoxy. 
     
     
       3. A compound according to claim 1, wherein R 5  and R 6  together represent a saturated 5- or 6-membered heterocycle having a maximum of 2 oxygen atoms as additional hetero atoms and which heterocycle is unsubstituted or substituted by one or two methyl groups. 
     
     
       4. An agricultural composition which contains, as active ingredients, a microbicidially effective amount of at least one compound of formula I according to claim 1, together with customary carriers and adjuvants. 
     
     
       5. A composition according to claim 4, wherein the active ingredient is a compound according to claim 2. 
     
     
       6. A composition according to claim 4, wherein the active ingredient is a compound according to claim 3.